For a reaction , a graph was plotted between reactant concentration `c` and time as shown in the figure below.

Identify the order of the reaction with respect to the reactant. Can the concentration of the reactant be theoretically zero after infinite time?

Explanation

form graph, it is evident that
a. Concentration of `40` reduced to `20` in `5 min`.
b. `20` reduced to `10` in `5 min`.
c. `10` reduces to `5` in `5 min`.
i.e., half is independent of concentration which is characteristic of first order. In first order, the concentration of the reactant can never be the theoretically zero.